<!DOCTYPE html>
<html lang="en">
<head>
  <title>Page with link to a very slow page</title>
  <meta charset="UTF-8">
</head>
<body>
  <h1>Page with link to a very slow page</h1>

  <a id="slow-link" href="start_page.html?duration=1200">Link to slow page</a>
  <a id="slow-hidden-link" href="start_page.html?duration=1200" style="display: none">Hidden link to slow page</a>

<script>
  setTimeout(() => {
    document.getElementById('slow-hidden-link').style.display = 'block'
  }, 1000)
</script>
</body>
</html>
